Armrests are generally used to rest an arm of an occupant of a seat or a passenger of an automobile. A conventional armrest for automobile seat, for example, is placed on an automobile seat so that an occupant can put her/his arm on it or positioned parallel with the back of the automobile seat by pivoting it upward when not in use.
Conventional armrests have a problem in that its inclination may not be adjusted, even if the occupant wants so for reading or taking a comfortable posture.